The discovery of a collection of bone tools in northern Tanzania’s Olduvai Gorge has provided an extraordinary glimpse into the technological abilities of early human ancestors. Unearthed by archaeologists, these artifacts—dated to 1.5 million years ago—now stand as the oldest known bone tools, predating previous discoveries by nearly a million years. This groundbreaking find challenges long-held assumptions about the cognitive and technical abilities of early hominins, demonstrating that our ancestors were far more advanced in their ability to manipulate materials than previously believed.
For decades, archaeologists have uncovered evidence of early tool use, with stone tools dating back at least 3.3 million years. However, bone tools have been significantly rarer in the archaeological record. Until this recent discovery, the oldest known bone tools were found at sites in Europe, estimated to be between 250,000 and 500,000 years old. The newly discovered tools—27 fragments of large mammal limb bones, primarily from hippopotamuses and elephants—show clear signs of deliberate shaping and sharpening, likely with the aid of stone tools. The longest of these artifacts reaches nearly 15 inches (38 centimeters), suggesting they were designed for specific heavy-duty tasks.
The uniformity in the design of the tools suggests that early hominins applied systematic techniques in crafting them, mirroring the processes used for stone tool production. This remarkable discovery hints at a level of cognitive sophistication that had not previously been associated with hominins of this era. The study, published in the journal Nature, indicates that early human ancestors were capable of abstract reasoning—an essential ability for making connections, identifying patterns, and innovating upon existing technologies.
Dr. Ignacio de la Torre, the study’s lead author and a scientist at the Spanish National Research Council’s Institute of History, emphasized the implications of the find, stating that it expands our understanding of early hominin technological capabilities. “This expansion of technological potential indicates advances in the cognitive abilities and mental structures of these hominins, who knew how to incorporate technical innovations by adapting their knowledge of stone work to the manipulation of bone remains,” de la Torre explained.
Olduvai Gorge: A Window into Human Evolution
Olduvai Gorge is one of the world’s most significant archaeological sites, often referred to as the “Cradle of Humankind.” Located in East Africa, this UNESCO World Heritage site has provided unparalleled insights into human evolution. It is where some of the earliest evidence of tool use and production has been discovered, alongside fossilized remains of early hominin species such as Homo habilis, Homo erectus, and early Homo sapiens.
The significance of Olduvai Gorge in the study of human origins cannot be overstated. The site’s timeline spans from around 2 million years ago to 20,000 years ago, allowing researchers to trace the evolutionary development of hominins over an extensive period. Throughout this timeline, archaeological evidence reveals important cultural and technological advancements.
Study coauthor Jackson Njau, an associate professor in the Department of Earth and Atmospheric Sciences at Indiana University, expressed his deep connection to the site. “As a Tanzanian native, I’ve been captivated since my high school days by the groundbreaking discoveries made at Olduvai Gorge,” he said. “The iconic work of Drs. Louis and Mary Leakey, who uncovered early human fossils and some of the world’s first human stone tools, ignited my fascination and fueled the dreams of countless young students, myself included.”
The evolution of toolmaking at Olduvai Gorge is a fascinating subject. During the Oldowan period—named after the stone artifacts found at the site—hominins used simple tools created by striking one rock against another, producing sharp flakes. These primitive tools, used between 2.7 million and 1.5 million years ago, mark the earliest known stage of human technology.
A major technological shift occurred around 1.7 million years ago during the Acheulean period, when early humans began crafting more complex tools, such as the hand ax. These large, almond-shaped stone tools required an advanced technique called knapping, in which small flakes were chipped away to create sharp, durable edges. The emergence of Acheulean tools represented a significant leap in early human innovation, demonstrating a deeper understanding of material properties and tool functionality.
Ancient Craftsmanship on Display
The discovery of the Olduvai Gorge bone tools adds a new layer to our understanding of early hominin craftsmanship. These tools were first identified in 2018 during a series of excavations conducted between 2015 and 2022. Researchers had been drawn to a particular gully in the gorge after discovering hominin teeth during a field survey between 2010 and 2011. This survey, co-led by Jackson Njau and Robert Blumenschine, a professor emeritus at Rutgers University, set the stage for the remarkable findings that followed.
The analysis of the bone tools revealed that their creators applied knapping techniques similar to those used for stone tools. The largest tools—made from elephant bones—measured between 8.6 and 15 inches (22 to 38 centimeters) long and 3.1 to 6 inches (8 to 15 centimeters) wide. Slightly smaller tools, crafted from hippopotamus bones, ranged from 7 to 12 inches (18 to 30 centimeters) long and 2.3 to 3.1 inches (6 to 8 centimeters) wide.
These artifacts provide an invaluable glimpse into early hominin ingenuity. According to study coauthor Dr. Renata Peters, an associate professor at the University College London’s Institute of Archaeology, the tools show clear evidence of deliberate crafting. “The tools show evidence that their creators carefully worked the bones, chipping off flakes to create useful shapes,” she said. “We were excited to find these bone tools from such an early timeframe. It means that human ancestors were capable of transferring skills from stone to bone, a level of complex cognition that we haven’t seen elsewhere for another million years.”
The findings indicate that hominins were experiencing a technological transition around 1.5 million years ago. Previously, archaeologists believed that early human ancestors primarily relied on stone tools during this period. However, the newly discovered bone tools suggest that hominins were expanding their technological repertoire, incorporating new materials and techniques.
New Mysteries Emerge
One of the biggest unanswered questions is which hominin species was responsible for creating these tools. No hominin remains were found directly alongside the artifacts, making it difficult to pinpoint the exact species. However, previous research at the site suggests that Homo erectus and Paranthropus boisei were present in the region during this time.
Another intriguing aspect of the discovery is the purpose of these tools. While there is no direct evidence indicating how they were used, researchers believe they were likely employed for tasks such as butchering animal carcasses or shaping other tools. The choice of dense, strong bones from large animals suggests that these tools were meant for heavy-duty applications.
Bone tools are significantly rarer in the archaeological record than stone tools because organic materials degrade more easily over time. However, this discovery suggests that bone technology may have been more widespread than previously thought. As study authors noted, the fact that 27 bone tools were found in one location implies a pattern of mass production rather than isolated instances of bone tool use.
Dr. Briana Pobiner, a paleoanthropologist at the Smithsonian National Museum of Natural History who was not involved in the study, emphasized the broader significance of the findings. “That there is a collection of 27 bone tools, and not just one or a few, suggests that hominins 1.5 million years ago were able to successfully transfer their knowledge of how to knap stone to knapping bone,” she said. “To me, this signals that toolmaking was becoming an increasingly important part of our ancestors’ lives.”
Pobiner also highlighted how these discoveries underscore the importance of reevaluating museum collections for overlooked evidence of hominin behavior. “Once again, we should be looking in museum collections for more evidence of bone tool manufacture earlier than we might have previously expected,” she noted.
This discovery reshapes our understanding of early hominin technological capabilities. It suggests that human ancestors were not merely passive scavengers but active problem-solvers capable of innovation and adaptation. The ability to manipulate different materials for toolmaking is a testament to the cognitive and creative abilities of our distant relatives, pushing back the timeline of advanced hominin behavior by nearly a million years.
More information: Ignacio de la Torre et al, Systematic bone tool production at 1.5 million years ago, Nature (2025). DOI: 10.1038/s41586-025-08652-5